HAS土壤固化剂对电镀污泥处理效果的研究

本课题采用HAS土壤固化剂代替传统固化基材对电镀污泥进行常温固化处理 ,在实现污泥无害化的基础上 ,探讨利用电镀污泥研制一种性能优良的“免烧免蒸”护坡砖的可行性。实验研究表明 ,固化块的机械性能、抗冻 融性能、耐干 湿性能均满足护坡砖的要求 ,并且浸出液中重金属离子的浓度在国家允许的范围内。因此 ,该固化工艺开辟了电镀污泥资源化利用的新途径     

Miocene to recent history of the western Altiplano in northern Chile revealed by lacustrine sediments of the Lauca basin (18°15′–18°40′ S/69°30′–69°05′W)

The intramontane Lauca Basin at the western margin of the northern Chilean Altiplano lies to the west of and is topographically isolated from the well-known Plio-Pleistocene lake system of fluvio-lacustrine origin that covers the Bolivian Altiplano from Lake Titicaca to the north for more than 800?km to the Salar de Uyuni in the south. The Lauca Basin is filled by a sequence of some 120?m of mainly upper Miocene to Pliocene clastic and volcaniclastic sediments of lacustrine and alluvial origin. Volcanic rocks, partly pyroclastic, provide useful marker horizons. In the first period (6–4?Ma) of its evolution, the 'Lago Lauca' was a shallow ephemeral lake. Evaporites indicate temporarily closed conditions. After 4?Ma the lake changed to a perennial water body surrounded by alluvial plains. In the late Pleistocene and Holocene (2–0?Ma) there was only marginal deposition of alluvial and glacial sediments. The basin formed as a half-graben or by pull-apart between 10 and 15?Ma (tectonic displacement of the basal ignimbrite sequence during the 'Quechua Phase') and 6.2?Ma (maximum K/Ar ages of biotites of tuff horizons in the deepest part of the basin). Apart from this early basin formation, there has been surprisingly little displacement during the past 6?Ma close to the Western Cordillera of the Altiplano. Also, climate indicators (pollen, evaporites, sedimentary facies) suggest that an arid climate has existed for the past 6?Ma on the Altiplano. Together, these pieces of evidence indicate the absence of large scale block-faulting, tilt and major uplift during the past 5–6?Ma in this area.     

Clues and pitfalls in the early prenatal diagnosis of ‘late onset’ infantile polycystic kidney

Infantile polycystic kidney disease (IPKD) is an autosornal recesive inherited disorder, IPKD has been previously diagnosed by us as early as the 14th week of gestation. ‘Late onset’ (third trimester) IPKD has been previously described by several authors. We present here a case of intrauterine detection of ‘late onset’ IPKD, suggesting that elongated hyperechogenic kidneys (with normal transverse and anteroposterior diameters) should be considered as an early sign of ‘late onset’ presenting IPKD.     

Comparative genomics: methods and applications

Interpreting the functional content of a given genomic sequence is one of the central challenges of biology today. Perhaps the most promising approach to this problem is based on the comparative method of classic biology in the modern guise of sequence comparison. For instance, protein-coding regions tend to be conserved between species. Hence, a simple method for distinguishing a functional exon from the chance absence of stop codons is to investigate its homologue from closely related species. Predicting regulatory elements is even more difficult than exon prediction, but again, comparisons pinpointing conserved sequence motifs upstream of translation start sites are helping to unravel gene regulatory networks. In addition to interspecific studies, intraspecific sequence comparison yields insights into the evolutionary forces that have acted on a species in the past. Of particular interest here is the identification of selection events such as selective sweeps. Both intra- and interspecific sequence comparisons are based on a variety of computational methods, including alignment, phylogenetic reconstruction, and coalescent theory. This article surveys the biology and the central computational ideas applied in recent comparative genomics projects. We argue that the most fruitful method of understanding the functional content of genomes is to study them in the context of related genomic sequences. In particular, such a study may reveal selection, a fundamental pointer to biological relevance.     

Epicuticular wax of large and small white butterflies,<Emphasis Type="Italic"> Pieris brassicae</Emphasis> and<Emphasis Type="Italic"> P. rapae crucivora</Emphasis>: qualitative and quantitative comparison between diapause and non-diapause pupae

We compared the quantity and quality of the epicuticular wax of diapause and non-diapause pupae in two closely related Pieris species, P. brassicae and P. rapae crucivora. Main components of their epicuticular wax were identified as hydrocarbons. In P. brassicae, more than 95% of hydrocarbons were saturated regardless of whether the pupae were in diapause or not. In P. rapae crucivora, 93% of hydrocarbons were saturated in non-diapause pupae whereas in diapause pupae 41% were saturated and 59% unsaturated. From measurements of body surface area by nuclear magnetic resonance microimaging, we calculated the average thickness of the wax layer. The thickness in diapause and non-diapause pupae of P. brassicae was 800 and 160 nm, respectively. In P. rapae crucivora, the thickness was 195 nm in diapause and 11 nm in non-diapause. This is the first report to clarify the compositional difference in epicuticular wax between diapause and non-diapause pupae.     

Adsorption of acetanilide herbicides on soil and its components. II. Adsorption and catalytic hydrolysis of diethatyl-ethyl on saturated Na(+)-, K(+)-, Ca(2+)-, and Mg(2+)-montmorillonite

Adsorption and catalytic hydrolysis of the herbicide diethatyl-ethyl [N-chloroacetyl-N-(2,6-diethylphenyl)glycine ethyl ester] on homoionic Na⁺-, K⁺-, Ca²⁺-, and Mg²⁺-montmorillonite clays were investigated in water solution. The Freundlich adsorption coefficient, Kf, got from isotherms on clay followed the order of Na⁺ K⁺ > Mg²⁺ Ca²⁺. Analysis of FT-IR spectra of diethatyl-ethyl adsorbed on clay suggests probable bonding at the carboxyl and amide carbonyl groups of the herbicide. The rate of herbicide hydrolysis in homoionic clay suspensions followed the same order as that for adsorption, indicating that adsorption may have preceded and thus caused hydrolysis. Preliminary product identification showed that hydrolysis occurred via nucleophilic substitution at the carboxyl carbon, causing the cleavage of the ester bond and formation of diethatyl and its dechlorinated derivative, and at the amide carbon, yielding an ethyl ester derivative and its acid.These pathways also suggest that hydrolysis of diethatyl-ethyl was catalyzed by adsorption on the clay surface.     

Closely associated theropod trackways from the Jurassic of Zimbabwe

Eighty-eight tracks of large theropod dinosaurs were found in the mid-Jurassic of Zimbabwe. Among the tracks, at least five adjacent trackways are recorded. The adjacent tracks were probably made by animals traveling as a group, given that they are in relatively close succession; that there are three overlapping tracks (among just 23) suggesting reasonably close associations of the animals; that all the tracks are apparently of the same ichnotaxon; that the preservational types of the tracks are similar; and that the tracks are all of animals traveling in one general direction closely associated in time (there are no returning tracks of the same animals or of those of other species; presence of such tracks would be highly probable if the tracks were made over a period of time of even several hours). Nearby, recently discovered giant sauropod tracks, the first in sub-Saharan Africa, indicate a realistic potential of predator/prey interactions between the two groups of dinosaurs.     

Mating success and fidelity to territories in a fallow deer lek: a female removal experiment

A lek is a clump of male territories that females visit only for mating; it is quite a rare mating system among mammals. As we wanted to investigate the role of past male mating success on their fidelity to lek territories, we displaced fallow deer females by a lek (Lek A), i.e. we removed the resources for rutting males. They moved to a new area followed by some of the territorial males (mobile males) where they established a new lek (Lek B). Other males (faithful males) stayed on Lek A. The former had lower mating success and dominance ranking in the early, undisturbed part of the rut. After disturbance, the MS of faithful males was much reduced, while that of mobile males was higher on Lek B than it had been on Lek A. We then disturbed Lek B. Females returned to Lek A, and the mating success of faithful males reverted to its original level. Past mating success was the main factor predicting whether a male was faithful or mobile. We illustrated for the first time the importance of past experience in promoting lek fidelity; this experiment gives an insight into the mechanisms leading to the traditional use of leks.     

Predatory behavior in a necrophagous bee<Emphasis Type="Italic"> Trigona hypogea</Emphasis> (Hymenoptera; Apidae,Meliponini)

Although most bees feed on nectar and pollen, several exceptions have been reported. The strangest of all is the habit found in some neotropical stingless bees, which have completely replaced pollen-eating by eating animal protein from corpses. For more than 20 years, it was believed that carrion was the only protein source for these bees. We report that these bees feed not only off dead animals, but on the living brood of social wasps and possibly other similar sources. Using well developed prey location and foraging behaviors, necrophagous bees discover recently abandoned wasps nests and, within a few hours, prey upon all immatures found there.